Patent Literature 1 discloses as an input device of an electronic device a capacitance input device which detects a pressing position and a pressing force by using a change in capacitance produced between electrodes when one of opposing electrodes is pressed. The input device described in Patent Literature 1 includes one of the opposing electrodes provided on a substrate, and the other electrode provided to a displacement portion made of an elastic material such as rubber. When a user presses the displacement portion upon an input operation, a distance between the electrodes narrows, and the capacitance produced between the electrodes increases. Further, the input device detects a pressing position and a pressing force based on the change (increase) in this capacitance.
PTL 1: Japanese Patent Application Laid Open No. 2006-178742.
When the pressing force applied to the displacement portion in the input device described in Patent Literature 1 is low, the displacement portion is not sufficiently displaced to prevent narrowing of the distance between the electrodes, and the capacitance between the electrodes hardly changes. Hence, the input device described in Patent Literature 1 has a problem that, when the displacement portion is not pressed by a user with sufficient force upon an input operation, it is not possible to obtain a sufficient change amount in capacitance for detecting the pressing force so that neither the pressing force nor the pressing position can be detected.